1. Field of the Invention
This invention relates generally to synchronizing clutches. In particular, the present invention relates to a multiple friction member synchronizing clutch.
2. Description of Related Art
The addition or removal of frictional force is controlled by mechanical energy/force components, usually either by a single diaphragm-type spring or annular series of rocker arms attached to varying spring types, whose interaction with the other component is controlled by an axially/linearly movable throw-out bearing and actuation arm mechanism.
Generally, a friction member clutch is used to frictionally synchronize and connect the rotational speeds of two rotating components. Most other friction clutches utilize direct plate-to-plate contact. In these types of known clutches, frictional force is controlled by mechanical components, typically either a diaphragm-type spring, curved face torsion forced pressure members, or rocker arms attached to compression or tension springs on one rotating component whose interaction with the other component is controlled by a throw-out bearing.
Regardless of the mechanical energy components involved, the initial position of the system is with the rotation plates in contact because the spring components are highly preloaded for their initial position of final engagement.
In the case in which the clutch assembly uses a diaphragm spring, an axially mounted throw-out bearing is connected to radially inward-pointing fingers of the spring while the base of the spring, along its circumference, is attached to the pressure plate, connected via splines to its rotating shaft. As the throw-out bearing is moved axially about the shaft the diaphragm spring relieves force on opposing component by pulling the plate/diaphragm spring/bearing assembly away, reducing their normal force, friction and thus their rotation. Conversely, the throw-out bearing can also be moved axially to allow force from the spring to move and then press the plate assembly back into the opposing component, resuming friction and rotation. Many variations of the diaphragm spring assembly and its degrees of freedom/movement possibilities are popular in passenger vehicles.
In the case in which the clutch assembly uses rocker arms and springs, the springs are mounted in a housing, which pulls both plates together. Depending on the spring type (compression, tension, torsion, etc.) the look and specific geometry of the rocker arm and plate will be affected. The rocker arms are connected to the springs, the throw-out bearing, and the pressure plate housing. As the throw-out bearing moves axially along the shaft, the rocker arms act on the springs and rocker arm mechanism, relieving the forces between the pressure and fly plates and discontinuing the rotation. Conversely, as the throw-out bearing returns to its original position the springs reintroduce forces between the plates and friction/rotation resumes. The rocker arm type clutch assembly is popular with vehicles that carry larger loads such as tractor-trailers and tractors.